The US President added that the popular video-sharing app could be barred as soon as today (1 August), according to reports.
Speaking to reporters on Air Force One as he returned from Florida, he said: "As far as TikTok is concerned, we're banning them from the United States."
He then added: "Well, I have that authority. I can do it with an executive order or that [emergency economic powers]."
According to the BBC, US security officials have expressed concern that the app, owned by Chinese firm ByteDance, could be used to collect the personal data of Americans.
A TikTok spokesperson told LADbible: "These are the facts: 100 million Americans come to TikTok for entertainment and connection, especially during the pandemic. We've hired nearly 1,000 people to our US team this year alone, and are proud to be hiring another 10,000 employees into great paying jobs across the US.
"Our $1 billion creator fund supports US creators who are building livelihoods from our platform.
"TikTok US user data is stored in the US, with strict controls on employee access. TikTok's biggest investors come from the US.
"We are committed to protecting our users' privacy and safety as we continue working to bring joy to families and meaningful careers to those who create on our platform."
In a TikTok press release, written by the company's CEO Kevin Mayer, he said: "With our success comes responsibility and accountability. The entire industry has received scrutiny, and rightly so.
"Yet, we have received even more scrutiny due to the company's Chinese origins. We accept this and embrace the challenge of giving peace of mind through greater transparency and accountability.
"We believe it is essential to show users, advertisers, creators, and regulators that we are responsible and committed members of the American community that follows US laws."
He went on: "Beyond our commitment to accountability, we also believe all players in the industry should make a positive impact in the community. Our $200 million Creator Fund will help American creators get the most out of TikTok, and we expect that this will grow to over $1 billion in the US in the next 3 years, and more than double that globally.
"In addition to supporting these creative entrepreneurs, we are also on track to create 10,000 new TikTok jobs across the US."
You can read the full statement here.